fix: preserve openai ws flags in scheduler cache

backend/internal/repository/scheduler_cache.go

@@ -426,6 +426,13 @@ func filterSchedulerExtra(extra map[string]any) map[string]any {
 		"window_cost_sticky_reserve",
 		"max_sessions",
 		"session_idle_timeout_minutes",
+		"openai_oauth_responses_websockets_v2_enabled",
+		"openai_oauth_responses_websockets_v2_mode",
+		"openai_apikey_responses_websockets_v2_enabled",
+		"openai_apikey_responses_websockets_v2_mode",
+		"responses_websockets_v2_enabled",
+		"openai_ws_enabled",
+		"openai_ws_force_http",
 	}
 	filtered := make(map[string]any)
 	for _, key := range keys {

backend/internal/repository/scheduler_cache_unit_test.go

@@ -0,0 +1,33 @@
+//go:build unit
+
+package repository
+
+import (
+	"testing"
+
+	"github.com/Wei-Shaw/sub2api/internal/service"
+	"github.com/stretchr/testify/require"
+)
+
+func TestBuildSchedulerMetadataAccount_KeepsOpenAIWSFlags(t *testing.T) {
+	account := service.Account{
+		ID:       42,
+		Platform: service.PlatformOpenAI,
+		Type:     service.AccountTypeOAuth,
+		Extra: map[string]any{
+			"openai_oauth_responses_websockets_v2_enabled": true,
+			"openai_oauth_responses_websockets_v2_mode":    service.OpenAIWSIngressModePassthrough,
+			"openai_ws_force_http":                         true,
+			"mixed_scheduling":                             true,
+			"unused_large_field":                           "drop-me",
+		},
+	}
+
+	got := buildSchedulerMetadataAccount(account)
+
+	require.Equal(t, true, got.Extra["openai_oauth_responses_websockets_v2_enabled"])
+	require.Equal(t, service.OpenAIWSIngressModePassthrough, got.Extra["openai_oauth_responses_websockets_v2_mode"])
+	require.Equal(t, true, got.Extra["openai_ws_force_http"])
+	require.Equal(t, true, got.Extra["mixed_scheduling"])
+	require.Nil(t, got.Extra["unused_large_field"])
+}

backend/internal/service/openai_account_scheduler_ws_snapshot_test.go

@@ -0,0 +1,62 @@
+//go:build unit
+
+package service
+
+import (
+	"context"
+	"testing"
+
+	"github.com/Wei-Shaw/sub2api/internal/config"
+	"github.com/stretchr/testify/require"
+)
+
+func TestOpenAIGatewayService_SelectAccountWithScheduler_UsesWSPassthroughSnapshotFlags(t *testing.T) {
+	ctx := context.Background()
+	groupID := int64(10105)
+	account := &Account{
+		ID:          35001,
+		Platform:    PlatformOpenAI,
+		Type:        AccountTypeOAuth,
+		Status:      StatusActive,
+		Schedulable: true,
+		Concurrency: 10,
+		Extra: map[string]any{
+			"openai_oauth_responses_websockets_v2_mode": OpenAIWSIngressModePassthrough,
+		},
+	}
+
+	snapshotCache := &openAISnapshotCacheStub{
+		snapshotAccounts: []*Account{account},
+		accountsByID:     map[int64]*Account{account.ID: account},
+	}
+	cfg := &config.Config{}
+	cfg.Gateway.OpenAIWS.Enabled = true
+	cfg.Gateway.OpenAIWS.OAuthEnabled = true
+	cfg.Gateway.OpenAIWS.APIKeyEnabled = true
+	cfg.Gateway.OpenAIWS.ResponsesWebsocketsV2 = true
+	cfg.Gateway.OpenAIWS.ModeRouterV2Enabled = true
+	cfg.Gateway.OpenAIWS.IngressModeDefault = OpenAIWSIngressModeCtxPool
+
+	svc := &OpenAIGatewayService{
+		accountRepo:        stubOpenAIAccountRepo{accounts: []Account{*account}},
+		cache:              &stubGatewayCache{},
+		cfg:                cfg,
+		schedulerSnapshot:  &SchedulerSnapshotService{cache: snapshotCache},
+		concurrencyService: NewConcurrencyService(stubConcurrencyCache{}),
+	}
+
+	selection, decision, err := svc.SelectAccountWithScheduler(
+		ctx,
+		&groupID,
+		"",
+		"session_hash_ws_passthrough",
+		"gpt-5.1",
+		nil,
+		OpenAIUpstreamTransportResponsesWebsocketV2,
+	)
+	require.NoError(t, err)
+	require.NotNil(t, selection)
+	require.NotNil(t, selection.Account)
+	require.Equal(t, account.ID, selection.Account.ID)
+	require.Equal(t, openAIAccountScheduleLayerLoadBalance, decision.Layer)
+}